Maps And Directions
Maps And Directions > History of Maps • Map Projections
Maps are guides or drawings that help people locate something, find travel
directions, or understand an area. There are many kinds of maps
— road maps help us find our way; topographical maps show land
elevations; geological maps show the locations of natural resources;
relief maps show landforms; thematic maps show patterns such as population
density, climate, or vegetation. Topological maps show information
without regard to correct distances or geographic attributes.
Maps are generally presented with the north facing upwards, the south facing downwards, the west facing toward the left, and the east facing toward the right.
Maps use a system of longitude and latitude. Lines of latitude run across the map and are called parallels. Lines of longitude, on the other hand, run from the North Pole to the South Pole and are called meridians. While each latitude line is parallel to every other latitude line, no two lines of longitude are parallel to each other. Instead, lines of longitude are about 70 miles apart at the equator. From there they converge progressively until they come together at the two poles.
The equator, whose latitude is zero degrees, divides the world into the Northern Hemisphere and Southern Hemisphere. In contrast, the Prime Meridian, which is at longitude zero degrees, divides the world into the Western Hemisphere and the Eastern Hemisphere. The Prime Meridian is an internationally established reference line that passes from north to south through the Royal Greenwich Observatory in London, England.
How are lines of latitude and longitude numbered? Well, starting from the equator, each degree of latitude, which is represented by a line, is numbered to the north and to the south. These lines go as far as the North Pole, at 90 degrees North latitude, and the South Pole, at 90 degrees South latitude. Lines of longitude are similarly numbered, but eastward and westward to the 180th meridian — located on the opposite side of the globe from the Prime Meridian.
When you combine latitude and longitude, you get a grid that geographers call a graticule. The locations on a map are indicated by correctly identifying the grid coordinates on the graticule. When naming the coordinates, the latitude is given first, followed by the longitude. When the latitude is referenced, it must be specified whether the location is north or south of the equator. Similarly, when the longitude is referenced, it must be specified whether the location is east or west of the prime meridian.
In recent years, several mapping algorithms have been developed to chart and describe the best routes to travel between geographic locations. Taking into account such factors as distance, speed limits, and traffic congestion, these sophisticated programs produce remarkably accurate results for popular driving directions sites such as Mapquest, Google Maps, Yahoo Maps, and Windows Live Local.
This site, MapsAndDirections.us, features a convenient directory of online map and driving direction resources as well as United States and World atlases. The scrollable state maps show cities and towns as well as Interstate, Federal, and State highways; they can be printed in sections and used as travel maps. The website also features an overview of map projections, including four world map examples that illustrate cylindrical and azimuthal projections.
Shop for Maps
Online Maps and Driving Directions
World Atlas and Map Resources
United States Maps
Related North American Maps
Copyright © 2003- Zeducorp.
All rights reserved.
About us. Contact us. Search.
For your convenience, certain links will open in new windows.
Maps And Directions Guide